5.7 Supercharged E85 fuel system diy project

Finally got my fuel system upgraded this week! I think I may actually be finished with engine mods now.

I'll go a little detailed for those who care to do anything similar but there's still a LOT of info I could add so please feel free to hit me up if you want to know more!

The truck
2016 Tundra 5.7 4x4
Previously dynod 566HP and 664TRQ (e70 fuel)

Prior Mods:
*TRD supercharger
*2.30 ZPE modular pulley
*Methanol/water injection (50/50)
*RCF throttle body
*Custom 4.5" intake (9" cone inside gutted TRD box)
*MSD fuel pump voltage booster(set to 16v at 6 psi)
"OEM FFV pump
*DW660 injectors
*DWR1000iL boost referenced FPR
*FFV "low pressure/non flex" mode delete (using OEM non flex fuel supply line.. No more short return back to the tank.. Only to the rail after leaving pump)
*Custom "Eddy Souza" -6an line to feed passenger side. (Using NX Express adapters)
*Doug Thorley Headers
*Dirty Deeds ("done dirt cheap") TRD replacement exhaust with 20" mufflers.
*Custom 2.5" tips/dumps after the rear
*Custom HPT tune

New mods:
*Ti450 high flow pump
*Fuel Injector Development 1000cc injectors
*All new custom PTFE lines. (-8an feed to dual -6an spilt. -6 an dual return to Y feeding -6an return through DWR1000iL)
*Custom "Math Smith Mod" fuel rail high flow mod
*Custom -8an to 3/8 bulkhead in stock canister. (again thanks Matt for the idea)

Implementing the new mods
Phase 1(new pump)
The first thing I did was get a new/used FFV pump canister and installed the ti450.
*thanks to David at Prospeed for his input on this.
I had originally bought a Ti525(the "hellcat" 470lph pump).
David said the 525 will burn up and they use the 450lph pump instead.

After digging into it, What I found was that the 525 draws a pretty good amount of extra amperage during normal operation compared to the 450 TiAuto pumps.
The issue we (and many others) run into is that our vehicles don't give a variable amperage like the Hellcat does. Therefore the 525 will be drawing full amps and high power constantly through wires not meant for that.
This often leads to early 525 failure.

Some vehicles run new fuel pump wires that can handle the extra load but I opted for the less high draw and just barely less flow ti450 high pressure pump.

So... 450 installed into a new canister on the bench at my own speed. Plenty of time to measure/order/install the appropriate hoses and clamps and verify everything fits.
Depending on if you use the stock canister or custom bulkhead you will need different diameter hoses.
10mm dia fits the stock barbs great but the custom 3/8 bulkhead I used required a 9mm on that end. They do make 9mm to 10mm x 160mm corrugated hoses.. But they're hard to find.

Phase 2 (new lines and fittings)
After getting the pump ready as a simple drop in/swap.. that would be my next step however with the new lines they needed to be ready to go first.
So phase 2 was drawing exactly what it would look like, what adapters I need.. Buying them and then making and assembling all the lines and laying them out to be certain I had it ready to go.

If you are going to connect a -6an line to the strock pump you'll need this for each connection:
Radium Fuel Pump Adapter, For Oem Pump, Lotus 2Zz-Ge
SKU:rad20-0032

I used a -8an bulkhead got the feed and the Radium adapter for the return and that bulkhead in itself is a whole nother write up.. another option would be to use this for both with either a 6an feed to a disk 6an Y... Or even a Radium fitting to a 6an female/8an male (what I was going to do originally.. Still have the fitting)

Also if you are planning to run ethanol be sure you get PTFE lines and PTFE connections for where they attach to the line. These look very similar to regular rubber but are different.

You can also just buy them preassembled.

Phase 3 (New pump and lines install)
Drop the tank, install pump.. run the lines... And put it all back together.
This took a solid few hours/half day.

After finding a few "oops that wasn't more than have tight" places it was running great at about 8psi higher than the stock FFV system.

Simple adjustment to the DW1000 brought it back to exactly the same pressure.

I drove it this way a few days to watch trims and make sure everything was nice and tight. Fuel trims all looked great as they were prior to the new pump/lines.

Phase 4
Now the injectors and rail mod.
I disassembled the new lines from the rails and pulled the 660s and stock rails.
Everything was cleaned and the fuel rails were carefully modified as seen in the pics opening up the beveled ends using a small step drill bit.
I made sure to hold the rail so that shards would fall towards the bit (down) and then gently sanded the end with 120 to remove any burrs or sharp spots
After each end I would use pressurized air from the closest injector hole to blow any foreign shavings out the moddified end.. Brit moving on the the next one.
After that the new 1000cc injectors went in with the new electrical pig tail adapters.... Then some silicone WD-40 to the rubber seals and careful reinstallation.
Started the truck and waited for fountains of fuel or vacuum leaks. Lol. Sprayed MAF cleaner at the injectors to see if there were any leaks... No leaks.. Smooth idle..all was well.

Then flashed the new HPT tune. (Previously calculated and done a different day)

This whole day took another 3 hours or so going nice and slow.

Final adjustments
The next few days was just taking it easy and making some changes to the tune to get the injectors and trims spot on

Today I added E85 to what I calculated 43 to 46% total ethanol and after driving around locked in at 43.3%

I'm super excited to get it back on the dyno and see what she does for one more final hoorah!

Hopefully this write up helps someone. Feel free to hit me up with questions or comments!

 

That’s so badass.

 

Thanks Keith!

 

This is awesome

That TQ # is a beauty

 

Good On Ya!!!

 

mighty fine.


this amount of power is good to see in a stock block.

that TQ....good lawd.


can we surmise that the methanol is providing the necessary cooling for the piston/rings?

I am digging the fuel delivery mods...well thought out.

and there's that 4.5" intake....it haunts me.

one more question....what size pulley is that? 2.3 inches? 58mm?

 

Let's see that RCF TB! With the updated fuel goodies, did you notice the benefits immediately or is it a mild case of placebo...granted, you should be better on all accounts...just gauging is all...? Looks incredible and you modifications this last year happened fast! Well done!

 

Can you explain more about the "FFV "low pressure/non flex" mode delete"? What it improves and how

Thank ya!

 

Thanks everyone!

 

Thanks again.

Yes, 2.30 pulley.

Also Yes, I use 50/50 methanol/distilled water to do 2 things.. 1. Cool cylinder temps and 2.add octane
Both of these of course, eliminate/reduce preignition in different ways.

However.. the water and cooling is MORE important in my opinion with our very tight ring lands. When they get overly hot... very bad things will happen fast. For THAT reason I opted for the injection in the first place.

To dive even deeper down that rabbit hole.. my testing has shown that I get basically the same horsepower and same timing (ie: LACK of pulled timing) running 93 +50/50 WMI ..OR... 70%ethanol fuel WITHOUT injection.
I dyno'd with e70 and e70 PLUS WMI(50/50) and saw no increase in power adding the WMI. I DID see significant power increase in 93 plus WMI.

It makes sense if you think about it.. the 30% extra fuel of e70 is doing the same thing as the water, keeping temps down and allowing more top end power/timing without knock.

So currently I only spray when running 93.

I DO think that its possible that running straight meth may help with e85/e70.. but thats something I havent gotten into and I have also heard straight meth can strip the rotor coatings too. (which some say wont hurt it anyway.. but Im not ready to go there just yet.)

 

Wow.....wish I had that kind or knowledge. A massive sleeper...

 

I'll upload pics from my phone here in a few...

Yeah I havent posted much.. been lurking on FB a lot but Im kinda over FB and coming back to the forums for my car stuff I think. Most of these mods have been on a year to 2 but I didnt post anything.

I searched online car-parts.c o m and ebay, etc looking for a RCF throttle body. Found one for like 250 bucks. Then I went and made my own 4.5" intake using couplers and pipe I found online and cut to size... cut the maf housing out of my oem (non SC) airbox lid and siliconed it into a hole in the new custom pipe.

When I dyno'd I was running out of power up top a little. You could see it drop around 5200. I never had a fuel pressure gauge but Im pretty sure that was holding me back.

I felt like it was peppier after the fuel upgrades but who knows. lol. probably all in my head! Haha

 

Absolutely!
Forgive the long post but I gotta cover all the bases and explain the difference in the systems to make sense....


So... the way the stock (NON flex) fuel system works, is:
It leaves the pump and goes straight to the drivers side rail (front).. exits through the rear and then goes through the passengers side rail (rear to front) where it exits through a 43.5 psi fuel pressure regular... and then back to the tank.

The way the stock (FLEX) fuel system works, in is:
It leaves the pump and goes into a fuel switching valve located on the frame just above the tank. This switch has a "Y" where it sends it out via 2 options. 1)to the rail and 2)back to the tank. The rail is always open and it always goes that way.
BUT... when in (gas/normal/low pressure mode) it ALSO allows gas to take the short leg of the Y back to the tank where it passes through a 43.5 psi fuel pressure regulator build into the canister. (see pictures in OP of the canister I pulled).
What this does it limits the pressure of the fuel "system" to 43.5. Gas will still travel to the rail then back to the tank via another return line, just line the non-FFV... BUT... We are essentially 'leaking' that sweet sweet nectar right back into the tank too.
FFV flex fuel/high pressure mode closes this short return of the "Y" and sends the fuel ONLY to the rail.. the same way the non-flex fuel trucks do.
Again it goes to the drivers side rail (front).. exits through the rear ... passengers side rail (rear to front) where THIS time it exits through a 60 psi fuel pressure regular... and then back to the tank.
And yes, in low pressure more it DOES still go through that 60psi fpr.. but it is at 43.5 psi due to the open short return through the other in-tank fpr... and the system will run and the lower pressure. So in low pressure mode that rail regulator does nothing.

OK.. still with me? lol.

SO....
The Mod:

• I bought the NON-FLEX FUEL TRUCK's supply line that leaves the pump and runs towards the rail. It connects to the top of the canister and runs to a break/connection just in front of the tank.(simple fuel line connection) Both trucks have the connection here, both the same style connection at this point... FFV coming from the swicth valve(one stlye fitting there). Non-flex coming from the canister(different kind of fitting than the one leaving the switch).
• So I removed the section that ran from the switch to the front of the tank (heading to the rail)
• I removed the FFV canister "out" line that ran to the switching valve.
• I installed the NEW "non flex truck supply line "to the top of the canister "out" and connected it back inline at the junction in front of the tank, exactly like on he non-ffv trucks.
• Lastly, I removed the short return line running from the switching valve back to the pump 43psi fpr and capped it.

Now the system is ONE simple loop.. leaves the pump... drivers side.. pass side.. 60psi fpr... return. No more dumping out fuel via the short return..no more hobbs swicthes or grounding relays to try and trick the truck to stay in high pressure mode. It physically cannot give my gas away anymore! lol

It ran great this way for a long time as my daily driver with the stock FFV pump and a boost-a pump voltage increaser... made 566WHP with this setup and an extra 6an jumper running from the start of the drivers rail to the start of the pass rail (lmk if you want to hear more on that).
If I had to do it again the only thing I would have done definitely is replaced the pump while I had the tank down.

 

Badass! Well done!!!!

What pulley is that? Have you had any issues with belt slip?

 

Here's the stuff I used for that -6an jumper I referenced above.. credit to Eddy Suoza. He's the one who shared it with me.

Basically 2 NX adapters.. 2 6an to 1/8npt... 1 6an line.

You can see in the pictures it takes fuel from the "in" at the drivers side and gives it a direct path into the passenger side rear while maintaining factory connections.

Seemed like a great way to make sure I didn't steal fuel from the passenger side.
Maybe it was unnecessary but I figured out was worth the cost just to be extra safe.

 

2.30 pulley. Yes it did slip at top end until I got the green belt.

 

Right on! Well, look into Griptec pulleys if you find yourself slipping again...their pulleys are legit for these applications!

 

Man thank you for the explanation. I did a post a while back to show how to upgrade the stock ffv pump and install an external filter at the front of tank. I hadn't ever seen that pressure regulator before and absolutely wish I would have had the wherewithall to bypass it like you did. I thought about it and figured the potential of it messing up some ECU settings was too high to do it without research. But you're saying I absolutely can bypass that regulator/switch at the tank without the dash lights or anything like that?

well done btw, and thank you for the thorough explanations

 

You're welcome Jake.
I believe there WILL be a dash light with this that I tuned out via HPTuners.

I unplugged the switch valve so it's possible that was the only reason for the DTC.

I plugged it back in when I upgraded everything this time so I'll scan to see if it's still in there (reporting but not setting the light off) tomorrow.

 

Hulk thanks. I actually had the Griptec. It was still slipping with that crazy thing! I'm a big fan of them too.

 

Plugged it back in but have no lines connected to it and uncapped ins/outs correct?

 

Yeah just the electric connector.

I had unplugged it I guess out of my mindset that everything else was disconnected so unplug it... but then was getting a "fuel (something) circuit low".
I removed the DTC but I know it would still show up when I scanned for dtcs as a silent code...

I plugged the electric connector back in the other day and scanned just now and there's no code. So it looks like you CAN do this without DTC issues by just leaving it plugged in electrically.

It will open and close the switching valve as it sees fit but there's nothing running to or from it after switching to the non-flex supply line. So now harm and the ecu didn't know any different.

 

Very interesting. Guess I'm going to have to pull the tank back down again. May have to wait until I can upgrade to the transferflow tank.

Just to beat a dead horse, the hi/low pressure switching comes from soley that valve and has nothing to do with variable power to the fuel pump itself?

 

I'm honestly not sure on the speed to the pump.
I'm certain that it routes it as I've said above and I've confirmed the 60 psi in the front FFV regulator and 43 in the in tank one.

If I had to guess I would say that the pump gets the same volts but it would be only a guess.

I can show you how to spoof it into hi mode via grounding the relay, if you want to do that.

That's what I did prior to the ffv line delete/ change to straight loop. I had it always in high pressure mode via electric override from the fuse box on the engine bay.

 

No rush, but I would absolutely take you up on the offer if you don't mind!

And, if you already did the relay grounding, and it switched valve to high full time; what made you decide to bypass the valve, which does the same thing?

Thanks again for being so helpful

 

Well... My WIFE says it's a sickness. She calls it "cantfreakingleavethatstupidtruckalone"... But I don't know if that's the official medical name..

Honestly it was a long bumpy road learning about and figuring out how to overcome and then eventually take control of.. The flex fuel ECU. Lol.

Yes, technically it should be doing the same thing when you ground out the relay.

I went from a boost activated Hobbs switch that would do it, to just pulling the relay, to just always grounding it... I think grounding it would work just fine but by the time I got to there I was just over fighting the thing and wondering if it was doing what I wanted it to do... I figured a couple bucks on that one fuel line and I'm done wondering forever.

Basically pull the relay that's labeled Fuel Pump VSV... I attached pictures of Jeff Talors truck that he shared with me, as well as the page from the FFV SC install that points to the relay.

You can ground it to the shown tab by solder or just get a really long end of the stripped wire and wrap the prong very tight so that it doesn't move and then plug it back in.

Grounded it to the inside of the engine bay..
Tested it by listening at the back drivers wheel while a friend touched the ground to frame while key was on.. you could hear it click.

 

Sweet ride man!!!

 

Thanks fellas! Welcome Marc!

I've played with GMs before out the Toyota is a completely different animal from my 2000s and 1990s GMs! Haha!

 

@4firemandan
I'm contemplating one last round of mods for my truck. Larger intake tube and injectors, apparently I'm very borderline on maxing out the TRD injectors and it's recommended that I go with a larger intake tube in conjunction with larger ones. Can the injectors be removed without also removing the TRD blower?